CICS Interview Questions (21 - 30)

21. What is the function of DFHMDF BMS macro?

The DFHMDF is BMS macro used to define individual fields on a CICS map such as position, length, and display attributes. It specifies field position, length, attributes, and field name. It also controls how a field is displayed, protected, or modified.

22. What is the difference between a symbolic map and a physical map in CICS?

Physical Map: The compiled version of the screen layout that defines how data is presented on the terminal.
Symbolic Map: A copybook used in application programs that provides field names and data structures corresponding to the physical map, facilitating data manipulation within the program.

23. How do you dynamically set the CURSOR position to a specific field?
What are the three ways available for a program to position the cursor on the screen?

Cursor position can be set in three different ways -

Static Positioning: By coding the IC in the filed definition, the initial position can be set.
Dynamic Cursor Positioning: By moving the ‘-1’ to the length field of the desired filed.
Relative positioning: Exact cursor location can be set by mentioning the numeric number in the SEND MAP command.

24. What are the attribute values of Skipper and Stopper fields?

Skipper Field Attribute (ASKIP): Makes the field non-display and non-modifiable. Cursor skips over the field.
Stopper Field Attribute (PROT): Makes the field protected (non-modifiable). Cursor can stop on the field, but input is not allowed.

25. What is the Modified Data Tag (MDT), and how are FSET and FRSET related to it?

MDT (Modified Data Tag): A bit associated with each screen field that indicates whether the field has been modified by the user.
FSET (Field Set): An attribute that forces the MDT to be set on, ensuring the field's data is sent to the application program, even if the user hasn't modified it.
FRSET (Field Reset): An attribute that resets the MDT, indicating that the field has not been modified.

26. How do you set the MDT option to ON status, even if data is not entered?

Use the FSET (Field Set) attribute in the BMS map definition. Set FSET in the ATTRB clause of the BMS map to turn on MDT, ensuring the field data is always sent to the program.

27. Each map is divided into numerous fields, with three common working storage fields for each. Mention them?

Three Common Working-Storage Fields for Each Map Field in CICS

fieldnameI: Input field (data entered by the user)
fieldnameO: Output field (data to be displayed)
fieldnameA: Attribute field (defines display and input attributes)

28. What is the common work area?

The Common Work Area (CWA) is a user-defined memory area in the CICS main storage that can be shared by multiple tasks or programs.

Key Points:

Defined in the System Initialization Table (SIT).
Accessed using EXEC CICS ADDRESS CWA(data-area).
Used to store global data accessible across transactions.

29. What is the definition of COMMAREA?

COMMAREA is a data-passing mechanism in CICS, used to share information between programs or transactions during task execution.

Key Points:

Defined in the Linkage Section of the program.
Data is passed using the EXEC CICS LINK, XCTL, or RETURN commands.
Must be explicitly populated and handled by the program.

30. How would you classify all the CICS programs?

The programs can be classified into the following types based on program storage and execution behavior in CICS:

Transient Programs – Loaded and deleted after execution.
Resident Programs – Remain in memory after execution for faster reuse.
Quasi-Resident Programs – Initially transient but retained in memory due to frequent usage.
Library Programs – Stored in a CICS library (DFHRPL) and loaded as needed.